Machine for cutting threads on wood-screws.



0; KIRSGHKE. MACHINE FOR CUTTING THREADS 0N WOOD SG REWS.

APPLICATION FILED APR.1,1909.

- Patented Dec.6,1910.

HEET 1. 1

APPLICATION FILED APR. 1, 1909.

Patented Dec. 6,1910.

3 BHEETBBHEBT 2.

WITNESSES 0. KIRSGHKE. MACHINE FOB. CUTTING THREADS 0N WOOD SCREWS.

. APPLIOAT ION FILED APR. 1, 1909.

Patented Dec. 6, 1910.

3 SKBET8SHEET 3.

mm: 5511s .INVENTBK rs: NORRIS PETERS co, WASHINGTON, D. c,

UNITED STATES PATENT OFFICE.

OTTO KIRSCHKE, OF NUREMBERG, GERMANY, ASSIGNOR TO THE FIRM OF J. G.KAYSER, 0F NUREMBERG, GERMANY.

MACHINE FOR CUTTING THREADS ON WOOD-SCREWS.

Specification of Letters Patent.

Patented Dec. 6, 1910.

Application filed. April 1, 1909. Serial No. 487,246.

To all whom it may concern:

Be it known that I, OTTO Krnsoi-rxn, whose post office address is No. 1Sybelstrasse, Nuremberg, Bavaria, Germany, have invented certain new anduseful Improvements in Machines for Cutting Threads on \Vood-Screws; andI do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same.

This invention relates to a machine for cutting threads on wood screws,and its chief feature is that the cutting tool is mounted and moved in aspecially suitable manner.

The invention is shown by way of example in the accompanying drawings,in which Figure l is a front elevation of the machine, Fig. 2 a planview, and Fig. 3 a side elevation of Fig. l seen from the left. Fig. 4is a section on the line AB of Fig. 1. Fig. 5 is a detailed view of theslide, and Fig. 6 a side elevation of Fig. 1 seen from the right.

The shaft 2 is rotatably mounted in the machine frame 1 which shaft isdriven by the belt pulley 3. The shaft 2, carries the jaws 4, whichserve for holding the piece of work 5. The construction of these jaws aswell as their function is known and need not be described here. Moreoverthe apparatus by means of which the various screw bolts are taken from areceptacle and fed to the jaws has been omitted in the drawings ashaving no bearing on the invention.

Two toothed wheels 6 and 7 are mounted on the shaft 2, of which thetoothed wheel 7 rotates the tool 16 by means of the toothed wheels 8, 9,10, 11, 12 and 13 the worm 14, and the worm wheel 15, while the toothedwheel 6 by means of the toothed wheels, 17, 18, 19, 20 and 21 drives thecam shaft 22.

The rotating tool 16 is rotatably and approximately mounted in an arm23, and is directly driven by the worm wheel 15. As may be seen fromFigs. 3 and 4, the tool 16 acts from the top on the piece of work 5, sothat the turnings falling down and the cooling liquid do not damage thetool at the driving parts. The arm 23 carrying the tool 16 is rotatablymounted on a rod 25 by means of a sleeve 24, and is prevented frommoving longitudinally by means of a clamping mufi or sleeve 26, which isfixed to the rod 25 and loosely incloses the flange 27. The rod 25extends the whole length of the machine and is provided with a roller 28which engages in the groove 29 of the disk 31 mounted in the slide 30.The disk 21 is rotatively mounted in the slide 30 and can be fixed bymeans of the screw bolt 32. The slide 30 is provided with two arms 33and 34, which are connected with the cams 35 and 36, mounted on theshaft 22. When the shaft 22 is rotated, the slide 30 is moved to and froin a transverse direction, so causing the rod 25, and consequently thearm 23, carrying the tool, to reciprocate in the longitudinal directionof the machine. The clamping muff or sleeve 26 may be moved and adjustedon the rod 25, with the tool carrier made up of the parts 23 and 24, soas to suit the particular length of the piece of work 5 and may then befixed once more.

The tool carrier is moved to and from the piece of work by the followingarrangement. A double lever 37 is rotatively mounted on the tool holderbox 24, outside the machine frame. This double lever is in contact onthe one end by means of the extension 38, with the cam disk 39, mountedon the cam shaft 22, and on the other end is provided with a yoke 40,which carries a sliding piece 41. This sliding piece is mounted in theyoke and is adapted to be adjusted in the longitudinal direction bymeans of the spindle 42 and in the transverse direction by means of thescrew bolt 43. An arm 44 is clamped on the tool holder sleeve 24, whicharm slides on the sliding piece 41 by means of an adjustable bolt or pin45. The arm 44 is therefore rigidly connected with the tool holder 23,so that the move-' ment acting on the bolt 45 is transmitted to thetool. Owing to the adjustability of the sliding piece 41, the movementof the tool may be exactly adapted to the cross section of the screwbolt to be cut.

In order to effect a separation of the turnings or cuttings from thefinished screw bolts, the following arrangement 1s provided under themachine. Plates of sheet metal 48 and 49 are so mounted on the shafts 46and 47, respectively that the two plates may be swung downward when cuttng the screw, so forming a wide opening under the machine through whichthe turnings and cooling liquid may fall or pass while these sheet metalplates form a closed sloping track on which the finished screw may slidedown toward the front, see Figs. 3 and 4. The two sheet metal plates aremoved by a double lever 51 mounted on the axis 50 and contacting bymeans of the extension 52, with the cam disk 53, mounted on the shaft 22and which lever moves or swings the two sheet plates, 48 and 49 by meansof the arms 54 and 55. The double lever 51 is returned by a helicalspring 57, secured to the arm 56.

The screw bolt 5 held by the jaws 4 is assisted and supported in a knownmanner during the cutting by a counter bearing 58.

The machine hereinbefore described works as follows: The belt pulley 3mounted on the shaft 2 directly drives the jaws 4 holding the screw bolt5 while the tool is rotated by means of the toothed wheel transmissiongear 8-15 and the toothed wheel transmission gear 6 and 17-2l rotatesthe shaft The tool 16 is arranged at the point or t1p of the screw boltand is guided along the bolt by means of the feeding or pushing device2836, by the movement of the rod 25. By doing this the bolt 45 of thearm 44 firmly connected with the tool holder slides along the slidingpiece 41 thus guiding the tool 16. The cam disk 39, according torequirements lowers or raises the double lever 37, carrying the slidingpiece 41 and. moves the tool holder to or away from the work. The camdisk 39 is so adjusted that the tool when cutting the thread is pressedagainst the work by the double lever 37 and by the arm 44 and during theinoperative stroke or travel, that is during the return movement of thetool into the initial position, is moved away from the work owing to therecess in the said disk. The tool is moved away from the work inconsequence of its weight and is further assisted by the helical spring59. The turnings or cuttings produced during the cutting process and thecooling liquid pass down the sheet metal plate 48 under the machine (seeFig. After the thread has been cut the counter bearing 58 returns in aknown manner, jaws 4 open, the finished screw falls out and a new screwto be cut is inserted in the jaws by a known device. In the meantime thetwo plates 48 and 49 have been moved into the inclined or slopingposition shown in Fig. 4, so that the screw dropping off falls out infront. After the counter bearing 58 has moved up to the new bolt againand a pointed knife usually employed has initially cut the point of thebolt, the rotating cutting tool 16 has already reached the end point ofthe bolt 5 and is now again caused by the lever 37 and the arm 44 toapproach or more up to the screw bolt. Owing to the inclined surface ofthe rail or sliding piece 41, the tool is guided as far as the center ofthe screw bolt in order to out first of all the point or tip andthereafter finish cutting the screw.

The rotating tool 16 is clamped in a known manner in the sleeve 60 andis driven by the worm wheel 15 as already mentioned.

The worm 14 driving the worm wheel 15 rotates at the same speed as thespindle 2 and consequently also at the same speed as the screw bolt 5held by the jaws 4. The worm wheel has a few teeth more than the tool 16rotated by it. As the tool and the work have also to cooperate after themanner of a worm gear, and as however the tool 16 has a few teeth lessthan the worm wheel 15, driving it, the tool in order to make good orequalize the difference, must slide along the piece of work at a certainspeed beside rotating thus making the cutting of the thread possible. Ifthe tool were to have the same number of teeth as the worm wheel 15,then a mere worm transmission gear between tool and bolt would exist andit would be impossible to cut the thread.

lVhat I claim and desire to secure by Letters Patent is:

1. A machine for making wood screws comprising in combination, means forholding and rotating the work, a tool holder, a cam shaft, alongitudinally reciprocating rod carrying said holder, a slide angularlydisposed with respect to said rod and reciprocated by said cam shaft,and an adjustable disk on said slide provided with a groove, said rodhaving a roller engaging said groove.

2. A machine for making wood screws comprising in combination, means forhold ing and rotating the work, a tool holder, a sleeve on which saidholder is mounted, a longitudinally reciprocable rod supporting saidsleeve, means for reciprocating said rod, and means connecting saidsleeve with said rod to permit oscillation of the sleeve and preventlongitudinal movement of the sleeve with respect to said rod.

3. A machine for making wood screws comprising in combination, means forholding and rotating the work, a tool holder, a sleeve on which saidholder is mounted, a rod for reciprocating said sleeve, means forreciprocating said rod, said sleeve having an arm provided with anadjustable screw 45, a rocking lever provided with an adjustableinclined rail engaging said screw for moving the tool holder toward andaway from said work.

at. In combination with a machine for form a slide, substantially as andfor the making wood screws, of means for operatpurpose set forth. 10 ingsaid machine, a plurality of pivotally In testimony whereof I affix mysignature mounted plates beneath the work operated in presence of twowitnesses.

on by the machine and normally swung OTTO KIRSCHKE. apart from eachother, and a device oper- Vitnesses:

ated by said means on completion of the AUSANDER VIELE,

work tor swinging said plates together to I MAX SCHNEIDER.

